Answer:
The correct answers are option A. "tethering proteins to the cell cortex", B. "using barriers such as tight junctions", C. "tethering proteins to the extracellular matrix", D. "forming a covalent linkage with membrane lipids", E. "tethering proteins to the surface of another cell"
Explanation:
According to the fluid-mosaic model, the components of cell membranes are in constant movement forming a barrier to avoid unwanted exterior component internalization and to avoid the loss of precious internal components. This constant movement could cause that proteins move across the plasma membrane. But, this is avoided by several mechanisms including:
A. Tethering proteins to the cell cortex. The cell cortex is a rigid structure made of actin and actomyosin. Proteins found in the plasma membrane are tethered to this structure to restrict their movement.
B. Using barriers such as tight junctions. Tight junctions are barriers found in epithelia made of claudin and occludin proteins. These barriers are impenetrable, which avoid the movement of proteins in the cell membrane.
C. Tethering proteins to the extracellular matrix. The extracellular matrix is made of several proteins and macromolecules that provide a structural and biochemical support to cells that are nearby. Proteins could be tethered to this rigid structure as well.
D. Forming a covalent linkage with membrane lipids. The proteins in the cell membrane that form a covalent linkage with membrane lipids are known as lipid-anchored proteins, or lipid-linked proteins.
E. Tethering proteins to the surface of another cell. When cell-cell communication take place it is possible that proteins in the cell membrane got tethered to the surface of the other cell.
A.photosynthesis because algae is a type of plant.
<span><span><span>The experimental method is usually taken to be the most scientific of all methods, the 'method of choice'.</span><span> </span><span> </span><span>The main problem with all the non-experimental methods is lack of control over the situation.</span><span> </span><span>The experimental method is a means of trying to overcome this problem.</span><span> </span><span> </span><span>The experiment is sometimes described as the cornerstone of psychology</span>
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Ozone is formed by the reaction of of nitrous oxides and reactive organic substance catalyzed by sunlight. This is a photochemical reaction provided with ozone forming compounds and sunlight.
Acid rain is defined as nitrous(NO2) and sulfurous (SO2) compounds enter the atmosphere as smog thereby precipitating as acid rain. This is detrimental in the environment as well as in agriculture.
Global warming is precipitated by the burning of fossil fuels that increases carbon dioxide, a greenhouse gas that traps heat, in the atmosphere. The greenhouse effect is the main principle behind global warming.
Ocean acidification is when excessive carbon dioxide is dissolved in the oceans as carbonic acid thereby increasing the pH of the ocean. Increases in the pH of the ocean can affect the living conditions as well as industrial conditions near it.
Groundwater pollution is defined as contaminating the groundwater with the runoff from industrial agriculture including organic and inorganic wastes as well as infectious and nuclear wastes.
Algae blooms or algal blooms are precipitated by eutrophication or the increase in nutrients in water such as nitrogenous compounds and phosphorus from fertilizers. Eutrophication of water precipitates the abnormally high growth rate of algae.
Ozone layer destruction is associated with CFCs such as Freon and aerosols as these compounds neutralize and destroy ozone. These compounds form free radicals that convert ozone (O3) to oxygen (O2) thereby reducing its capability to protect the earth from UV radiation.
Deforestation is primarily caused by urbanization (cutting down trees to provide empty land in building structures) and industrial farming (converting forests into agricultural lands for farming).
<em>Answers: 1. H, 2. D, 3. E, 4. A, 5. B, 6. C, 7. G, 8. F</em>
